Sara Oikawa

PhD Student in Exercise Metabolism Research Group

Department of Kinesiology

Supervisor: Stuart Phillips

What is your research about?

My research examines the effects of nutrition/dietary
supplementation (specifically protein intake) on changes in
muscle mass, strength, and function in older adults. In our
lab, we look at rates of muscle protein synthesis (the rate
at which your body builds muscle) with the use of stable
isotope tracers that can be ingested (D2O) or
infused intravenously
(ring-13C6
phenylalanine). The focus of my current project is to
determine if there is a protective effect of consuming a
high protein diet on the previously mentioned outcomes
during reduced daily activity with a reduction in caloric
intake. We use reduced activity and a reduced caloric
intake in our model as it is quite representative of a
decreased appetite and reduced daily ambulation that occurs
during hospitalization or illness. Previously, it has been
shown that consuming large amounts of protein can stimulate
muscle protein synthesis and since individuals who are
hospitalized may not be able to exercise, nutrition may be
a feasible strategy to offset the loss of muscle that
occurs with inactivity.

What is the goal of your research?

We hope to better understand the role that protein,
specifically the role that high quality protein ingestion
(whey protein) plays in attenuating the loss of muscle
during periods of reduced daily activity as it may have
implications on nutritional provision in hospital and
clinical care. We also are looking to determine whether
functional changes that typically occur at the whole body
level (i.e. decreases in muscle strength or maximal
voluntary contraction) are reflective of changes at the
muscle fibre level.

Why does your research matter?

After about the 5 th decade of life, adults begin to lose
muscle mass at a rate of 1% per year with losses in
strength closer to 3% per year and these losses are
unfortunately accelerated during periods of disuse or
reduced activity that occur with illness, surgery or
hospitalization. This may result in the loss of
independence or a reduction in quality of life, as older
adults often do not recover from these events. That being
said, older adults (>60 years of age) make up ~15% of
the Canadian population but account for 45% of health care
spending. This is increasingly alarming as the population
of older adults is expected to double in the next 20 years
and thus strategies to slow muscle loss with age are
imperative.

What do you enjoy most about your research?

Hopefully our research can be translated into clinical care to improve nutrition for individuals who are unfortunately bed ridden in hospital or institutionalized care. I really enjoy the applicability of our research models and that we often have the opportunity to really impact public health knowledge. The opportunity to work with humans in our trials is also a huge draw for me. I get to meet and interact with interesting people everyday who are passionate about research and who are willing to donate their time and sometimes muscle and blood to help us answer a research question. Along with the participants, I am also surrounded by an incredible network in the department of kinesiology who are extremely supportive and always willing to collaborate.